The invention relates to a device for grinding and deburring a flat workpiece.
During punching or cutting of steel sheets that may well be several centimeters thick, interfering burrs form on the top side of the sheets. These may be ground off by means of a grinding roller. To this end, the workpiece is caused to pass under the relatively rapidly rotating grinding roller by means of a suitable transport mechanism.
DE 10 2007 048 544 A1 describes a device for grinding a flat workpiece with a grinding roller that is driven by an electromotor via V-belt pulleys and V-belts. The circumferential surface of the grinding roller is covered with abrasive paper or abrasive cloth.
A statically borne grinding roller wears unevenly, because the same locations of the abrasive coating always grind the surface of the workpieces. In German specification 1 502 538 it is therefore suggested that the grinding roller be moved back and forth in the transverse direction in order to effect uniform wear of the grinding roller. A connecting rod drive is mentioned as a possible mechanism for producing the back-and-forth movement of the grinding roller in the transverse direction.
U.S. Pat. No. 3,435,566 A describes a grinding and deburring machine having a grinding roller, the shaft of which is borne laterally displaceable in a bearing. No oscillating back-and-forth movement of the grinding roller is provided.
In electric toothbrushes, an electric motor causes a comparatively small brush to move simultaneously in a rotational movement and in an oscillating movement in the axial direction. In the toothbrush in accordance with U.S. Pat. No. 3,661,018 A, the drive shaft of the electric motor is coupled to a cam mechanism that causes the rotational movement of the motor in an axial up-and-down movement. However, in this case, the relationship between the rotational speed of the brush and the oscillation frequency is specified to be fixed. It is not possible to perform less than one oscillation movement per rotation of the motor or brush.
U.S. Pat. No. 4,397,055 describes an electric toothbrush having a small motor that is coupled to a cam mechanism such that the motor both causes the brush, which is embodied like a roller, to rotate and also causes it to oscillate axially. An oscillation frequency below the rotational speed of the motor is not possible in this case, either.
US 2009/007802 A1 describes a kitchen appliance in which the motor simultaneously produces a rotational movement and an oscillation movement for an exchangeable kitchen tool. The oscillation movement is produced by a cam mechanism.
In a large and heavy machine for grinding and deburring, a second drive can be provided that is independent of the primary drive, for the back-and-forth movement of the grinding roller in the axial direction. This has the advantage that the rotary speed of the grinding roller and the frequency of the axial back-and-forth movement may be selected completely independent of one another, or even adjusted during operation. However, providing a second, separate drive for oscillating the grinding roller makes the machine significantly more complicated and, therefore, not just more expensive, but also less reliable in operation.